The universe is filled with things that oscillate.
The earth rotates – we have the shift from day to night and back again.
The moon orbits the earth, causing the rise and fall of tides.
The earth orbits the sun. We experience the recurrence of the seasons.
Light and sound have frequencies.
Electromagnetic waves have frequencies.
The device you’re using now to read this (assuming it’s being viewed electronically) has a tiny crystal inside that generates a train of impulses: on / off / on /off. Those impulses drive the rest of the system.
String theory postulates that the universe itself is composed of tiny strings, vibrating, oscillating.
We breathe in and out.
Our hearts beat.
The fundamental operations of our cells may have a feedback oscillation component to them that drives the chemical reactions.
Even the human brain has a frequency, a frequency that changes depending on what we’re doing, slowing when we’re asleep or meditative, faster when we’re deep in thought or otherwise using our gray matter in an active way.
The last one is of particular interest to me. When you look at neural nets in computing, they’re often, at least initially, set up as a sort of function: data comes in, data goes out. You train the network to respond to the inputs, and then you feed it input and see what is gives you for output. For example, a neural net could be trained for the identification of letters in an optical character recognition (OCR) application, where the “read” letter is output based on images presented as input.
But the human brain is more than that.
Part of what makes the human brain incredible is its massive size, in terms of connections. Depending on where you read, the estimates are 100 trillion up to 1000 trillion connections. What is equally critical for me is the fact the it’s not just a one-way network. The human brain is interconnected. It not only receives stimulation from the outside world; it also stimulates itself, continuously. It feeds back. It influences itself. It oscillates.
You see images play before your eyes. You hear that damn song in your head that won’t go away. (“But it’s my head!”) You relive scenes both pleasurable and horrific. You dwell on things that affect your emotional state, even though, for that moment, the stimulus is your own mind.
What does that have to do with IF? Perhaps nothing. But it is an interesting topic for me, and there is a higher level sort of recurrence that might be applicable, which is the recurrence of thoughts and feelings in our mental spaces. You can see an example of this in an earlier blog about associations.
ResponsIF‘s “fuzzy” design with weighted topics, decaying topics, and responses keyed off of those topics seemed to lend itself to experimentation with oscillation.
The first attempt, which was not topic based, was a miserable failure. I tried to simulate feedback based solely on values approaching each other. Even with layers of variables in between, the values kept achieving a steady state, where nothing changed. Not a very interesting state of affairs.
I achieved better success by having both varying state and target values which flip-flopped based on the direction it was going. Not ideal, and not really feedback as such, but it did oscillate. There are a couple of samples in the ResponsIF repository that illustrate these, one being a traffic light and one being an oscillation sample.
I ended up discovering a different approach to recurrence which may hold promise. I think of it as “ripples in the pond”.
The basic setup is to have a long-term topic associated with a lesser-weighted response. The lesser weighting places the response at a lower priority, which means it won’t trigger as long as higher priority responses can. This behavior for this response is to add in a decaying topic. That topic then triggers a response which may itself add in a decaying topic. The fact the topics decay and that their responses add in new fresh topics causes a ripple effect. Topic A triggers topic B which triggers topic C, on and on, to the level desired. Each triggering topic decays, causing its effect to lessen over time. Once the temporary topics decay sufficiently, the original, lower-priority response triggers, and the process begins all over again.
From a normal mental process point of view, this is equivalent to having long-term topics triggering transient short-term topics, with the long-term responses recurring until satisfying conditions are met. A bit like nagging reminders…
This might have simple uses, but it can also have more advanced uses if you have multiples of these all going off at once. Which responses actually get triggered depends on the state of the system: what the various response needs and weights are. This means that the internal state of an NPC can vary over time, both in terms of what has been experienced by the NPC and what its long-term goals are, as well as any short-term influences. And the NPC can influence itself.